IMAGING FEATURES OF HEREDITARY PAPILLARY RENAL CANCERS

Purpose: Our goal was to describe the imaging features of hereditary p apillary renal cancer syndrome (HPRC), a new familial cancer syndrome. Method: Members of seven kindreds with HPRC comprising 78 individuals were screened with contrast-enhanced CT and abdominal US. MRI was per formed in three patients. Enhancement values and doubling times of sol id masses were determined from CT scans. Results: Seventeen of 78 (22% ) patients were affected. The HPRCs demonstrated lower enhancement (me an change in enhancement = 31 HU) than a comparable group of clear cel l tumors (mean change in enhancement = 67 HU; p = 0.00001). The median tumor doubling time on serial CT was 18 months. The HPRCs were relati vely hypovascular, enhanced uniformly, and grew slowly. Therefore, car eful measurements of the region of interest should be obtained before and after intravenous administration of contrast medium. Though US det ected only 45% of the lesions visualized on CT, it was useful in deter mining if lesions were cystic. Contrast-enhanced MRI demonstrated simi lar characteristics to contrast-enhanced CT. Conclusion: The tumors of patients with HPRC pose some diagnostic difficulties because they can be missed by US, are small, and enhance poorly on CT. CT is preferabl e to US as a screening tool because of its higher sensitivity in detec ting small lesions, and when contrast media cannot be administered, MR is a suitable alternative to CT.